Hearing instrument system

Abstract

A hearing instrument system is described, comprising a hearing instrument (1) with a housing (12) and at least one loudspeaker (8) arranged in the housing (12), which is connected to the environment of the housing (12) via a sound conduction channel (14). Furthermore, the hearing instrument system includes a controller (6) configured to determine whether at least one start condition for initiating a cleaning mode for the sound conduction channel (14) is present, to initiate the cleaning mode if the start condition or one of possibly several is present, and to emit an audio signal with a predetermined waveform and varying period via the loudspeaker (8) during the cleaning mode.

Description

[0001] The invention relates to a hearing aid system.

[0002] Hearing instruments are typically used to output an audio signal to the wearer's ear. This output is achieved via an output transducer, usually acoustically through sound waves transmitted via a loudspeaker (also called a "receiver"). Such hearing instruments are frequently used as hearing aids. They typically comprise an acoustic input transducer (especially a microphone) and a signal processor. This processor is designed to process the input signal (also called the microphone signal) generated from the ambient sound by the input transducer, using at least one user-specific signal processing algorithm, in such a way as to at least partially compensate for the wearer's hearing loss.Particularly in the case of a hearing aid, the output transducer can be a loudspeaker, a bone conduction receiver, or a cochlear implant, all of which are designed to mechanically or electrically couple the sound signal into the wearer's ear. There are also hearing instruments that protect or improve the hearing of users with normal hearing, for example, by enabling improved speech understanding in complex listening situations. Such devices are also known as "Personal Sound Amplification Products" (PSAPs). The term "hearing instruments" also includes devices such as tinnitus maskers, headsets, headphones (including earbuds), and similar devices.

[0003] Typical designs of hearing instruments, especially hearing aids, are behind-the-ear (BTE) and in-the-ear (ITE) hearing instruments. These terms refer to the intended wearing position. Behind-the-ear hearing instruments have a (main) housing that is worn behind the ear. A distinction can be made between models whose speaker is located within this housing—sound is typically delivered to the ear via a sound tube placed in the ear canal—and models that have an external speaker positioned in the ear canal. In-the-ear hearing instruments, on the other hand, have a housing that is worn in the ear or even entirely within the ear canal.

[0004] Hearing aids that use a loudspeaker obviously require an opening through which the sound generated by the loudspeaker can reach the surrounding environment, especially the user's ears. However, every opening also provides an opportunity for contaminants to enter the hearing aid, at least as far as the loudspeaker, or even inside it. Such contaminants include moisture (liquid or vapor) or particles (dust, lint, sand, or the like), but often also earwax. Due to ongoing miniaturization and the fact that the housings are usually sealed as tightly as possible, manual drying—except with the use of a blower—or cleaning is generally associated with a high risk of damage. Furthermore, such contaminants lead to a loss of function due to (partial) blockage of openings, for example.This can also affect sound transmission channels, or even lead to damage (e.g., corrosion) to the loudspeaker itself, if such contamination can penetrate into or onto the loudspeaker. Therefore, removing such contaminants is in the user's interest.

[0005] The invention is therefore based on the objective of enabling an improvement in the removal of impurities.

[0006] This problem is solved according to the invention by a hearing instrument system with the features of claim 1. Advantageous and partly inventive embodiments and further developments of the invention are set out in the dependent claims and the following description.

[0007] The hearing instrument system according to the invention comprises a hearing instrument and at least one loudspeaker. This loudspeaker is acoustically connected to the hearing instrument's surroundings via a sound conduction channel. Furthermore, the hearing instrument system comprises a controller configured to determine whether at least one start condition for recording (in particular, activating) a cleaning mode for the sound conduction channel is present, and, if one or more of the start conditions is present, to record (in particular, activate) the cleaning mode and, during the cleaning mode, to emit a (in particular, acoustic) tone signal (also: "sound signal") with a waveform via the loudspeaker. The controller is configured to vary the period of the waveform while the tone signal is being emitted.

[0008] Preferably, the controller is also configured to select and specify the rise and / or fall time of the signal edges of the audio signal, and in particular to change this during audio output. The rise and fall times are preferably varied within durations typical for an audio signal—for example, between 50 µs and 5 ms, and especially between 200 µs and 5 ms. Optionally, and in particular as described in more detail below, the controller is configured to change the rise and / or fall time of the signal edges when the period is changed. At least for a specified maximum amplitude (commonly referred to as volume or signal level), which may be constant, the slope of the signal edges, and thus their rise and fall times, also change when the period is changed.In addition, the controller can also be configured to select and, if necessary, change the rise and fall times of the signal edges, for example, depending on contamination. In the latter case, the period changes accordingly (especially while maintaining the specified maximum amplitude).

[0009] The term "signal edge" is used here and in the following to refer specifically to the edge of an oscillating time signal. Therefore, the audio signal should preferably also be understood as an oscillating time signal.

[0010] Preferably, a maximum amplitude (i.e., a maximum value for the amplitude) is specified for the audio signal, particularly by the controller, and this amplitude remains constant throughout the duration of the audio signal. The amplitude values ​​that typically rise or fall at the beginning and end of the audio signal (due to "switch-on" or "switch-off" processes) are to be disregarded.

[0011] According to a particularly advantageous embodiment, the controller is configured to output the audio signal with a varying period in the form of at least one chirp. Here and in the following, a chirp is understood to be an acoustic event, especially an audio signal, whose frequency (and thus also its period) changes over time. In particular, the frequency can increase or decrease—preferably while the waveform and / or amplitude (especially at least the maximum amplitude, as described above) of the signal remains constant. In particular, a chirp—at least within the scope of this description—is thus described by several properties (parameters) such as a duration (usually several seconds, e.g., 3 to 20 seconds), a start frequency, and an end frequency, as well as its underlying waveform. In particular, the change in frequency of the chirp occurs continuously from the start to the end frequency.The chirp is thus preferably distinguished from two successive tone signals with different (constant) frequencies.

[0012] Preferably, the hearing aid system includes a housing for the hearing instrument (i.e., the housing is part of the hearing instrument). Optionally, the loudspeaker is arranged within the housing. The housing can also serve as a housing for several components of the hearing instrument (e.g., for the controller, a microphone, and a power source such as a battery) or as a housing (in this case, preferably as an add-on housing component) solely for the loudspeaker. In the latter case, this add-on housing component forms, in particular, an earpiece designed and intended for holding the loudspeaker in the ear, preferably the ear canal, of a user.

[0013] In its simplest form, the sound conduction channel can be a sound opening in the housing (or corresponding housing component) containing a sound outlet of the loudspeaker – e.g., a spout or similar – or connecting a corresponding sound output opening of the loudspeaker to the inside of the housing. However, the sound conduction channel can also be formed by a tube- or hose-like component (especially separate from the loudspeaker) that connects the sound output opening of the loudspeaker to the sound opening of the housing (especially the earpiece) or to another sound emission opening (the latter being particularly common in the case of a sound tube).

[0014] The sound signal, due to its sound pressure and / or the resulting vibrations in the sound conduction channel, advantageously causes the transport of contaminants. This (material) transport can be used to clear the sound conduction channel of contaminants (in particular, to clean them) or at least to partially remove or disperse them, thus enabling sound output through the sound conduction channel and / or preventing the contaminants from reaching the loudspeaker. Therefore, the sound signal can also be referred to as an (acoustic) "cleaning signal" in the following.

[0015] A chirp has the advantage that the cleaning signal is not only emitted at a fixed frequency, but across a frequency range, i.e., at least two frequencies. This improves the transport effect, especially since contaminants are usually not homogeneous and thus different parts of the contaminant "respond" to different frequencies (and can therefore be moved).

[0016] According to a particularly advantageous design, the controller is configured to detect the type of contamination in the sound conduction channel and to select a waveform for the audio signal, especially the chirp, depending on the type of contamination. This is based on the understanding that different types of contamination, such as (especially dry) particles (e.g., dust) or liquids (e.g., sweat, water), have different waveforms that affect the transmission of the respective contamination through the sound conduction channel to varying degrees.

[0017] According to another practical embodiment, the controller is configured to select a frequency range, i.e., in particular the start and end frequencies, for the audio signal, especially the chirp, depending on the level of contamination, either in addition to or as an alternative to selecting the waveform. This embodiment is also based on the understanding that liquids and particles in the sound conduction channel react differently to different frequencies, and that the transport through the sound conduction channel can thus be influenced accordingly.

[0018] To determine the type of contamination in the sound conduction channel, the controller is configured, according to a particularly suitable embodiment, to perform a (particularly acoustic) feedback measurement, specifically a so-called open-loop gain measurement. If the hearing instrument includes an associated microphone, especially if it is designed as a hearing aid, such a feedback measurement is known to be carried out by placing the hearing instrument freely or in a reference housing (e.g., in the housing of a charger) and outputting an audio signal with increasing amplification until feedback, i.e., a return of the output audio signal to its own microphone, is detected. A transfer function for feedback can be determined based on such a measurement. In the present case, the controller is specifically configured, for example, to...The system uses comparisons with stored references or training data and a learned algorithm to determine whether the sound conduction channel is clear, blocked with dry material (particles), and / or filled with liquid. An external microphone can be used as an alternative to the internal microphone. For example, a microphone from a smartphone (or a comparable device or computer) or even a charger for the hearing aid can be used, the pickup characteristics of which are known to the controller or are specified during the measurement process.

[0019] Alternatively or additionally to the feedback measurement described above, the controller, according to another suitable embodiment, is configured to determine the type of contamination by detecting a resonant imbalance, in particular a mechanical, magnetic, and / or electrical resonant imbalance. Mechanical resonant imbalance can be detected, for example, using an accelerometer to monitor changes in the vibration of the hearing instrument, especially the housing or the loudspeaker. The accumulation of material (particles and / or moisture) in the sound conduction channel regularly leads to altered vibration behavior. A similar principle applies to magnetic and electrical resonance, particularly of the loudspeaker.

[0020] In a further alternative or additional embodiment, the controller is configured to evaluate an optical image, i.e., a picture, captured by a separate camera, in particular a camera of a smartphone, tablet, computer, or the like, and transmitted to the controller to determine the type of contamination. The controller preferably uses pattern recognition methods, a comparison with reference images, or the like. For example, the controller is configured to instruct the user of the hearing aid system, or at least the hearing aid itself, to take a corresponding image of the interior of the sound conduction duct. This image is then made available to the controller for evaluation (e.g., by the user or alternatively, via a special application ("app")).

[0021] Preferably, the controller forms an element (a component) of the hearing aid itself. In a preferred embodiment, the controller is at least essentially a microcontroller with a processor and a data memory, in which the functionality for carrying out the procedure described here and below according to the invention is implemented programmatically in the form of operating software (firmware), so that the controller—optionally in interaction with the user of the hearing aid—automatically performs the described steps when the operating software is executed in the microcontroller. Alternatively, within the scope of the invention, the controller can also be a non-programmable electronic component, e.g., an ASIC, in which the functionality described here and below for carrying out the cleaning mode is implemented by circuitry.Alternatively, the controller can be designed separately from the hearing aid and implemented, for example, in the aforementioned smartphone (or a comparable device, such as a computer, tablet, or similar device) (particularly via a software application). In this case, the smartphone forms part of the hearing aid system—at least during a properly established pairing with the hearing aid for control purposes. In this case, the smartphone expediently forwards the corresponding commands from the controller to the hearing aid (in particular, an associated internal hearing aid controller) to output the chirp (or optionally a "streaming signal" corresponding to the cleaning signal), preferably via a wireless connection.

[0022] According to a preferred embodiment, the controller is configured to select a square wave or a sawtooth waveform for the audio signal, particularly for the chirp. Both waveforms exhibit a high number of harmonic oscillations, which in turn has a positive effect on sound-driven transport of contaminants, especially in the case of moisture. A triangular waveform (especially with appropriately selected slopes or rise and fall times of the signal edges) also exhibits a high number of harmonic oscillations and is therefore optionally used. In principle, a sine wave can also be selected as the waveform for the audio signal, particularly for the chirp. As is known, square, triangular, and sawtooth waveforms differ in their respective slopes (rise and fall times), which are preferably selected by the controller.

[0023] According to a convenient embodiment, the controller is configured to select a sawtooth waveform for the audio signal, particularly for the chirp. In this case, the controller is also configured to select the slope of the rising edge (and thus, particularly in combination with a signal level, preferably constant and preferably predetermined – here preferably understood as the maximum amplitude of the audio signal – also its rise time) and the falling edge (and thus, particularly in combination with the signal level, preferably constant and predetermined, its fall time) of the sawtooth waveform depending on a transmission direction within the sound transmission channel. Thus, the controller is preferably configured to select the desired slope for a "positive" transmission direction, i.e.,The controller specifies a direction away from the loudspeaker, a steep (optionally approximately vertical) rising edge, and a shallow falling edge (each relative to the other) of the waveform. Preferably, the falling edge is significantly shallower (in particular, the slope is at least twice as shallow) than the rising edge. For a negative transport direction, i.e., towards the loudspeaker, the controller is configured—preferably conversely—to specify a rising edge that is shallower than the falling edge of the waveform. The negative transport direction can be advantageous in that the transport of (material) particles in the positive transport direction can be interrupted due to jammed or stuck particles. Such a "jam" can be resolved, for example, by reversing the transport direction, preferably multiple times.

[0024] Advantageously, the controller is configured, within the cleaning mode, to select the tone signal or at least two successive tone signals (in particular, to specify their respective slopes as described above) such that the transport direction changes. Optionally, the controller is configured, within the cleaning mode, for example, as part of the tone or cleaning signal or as an independent tone signal, to output a signal adapted for the negative transport direction, in particular a chirp, for a particularly short period, e.g., from 0.25 to 2 seconds, and, in particular, to follow this with another signal (partial signal or independent tone signal) for the positive transport direction. Advantageously, the controller is configured to combine the tone signal with a partial signal for the negative transport direction for a short period, e.g., from 0.25 to 2 seconds.The controller can emit a signal for up to 3 seconds, or even a (particularly short) tone signal alternately for each transport direction, i.e., repeatedly alternating signals for the positive and negative transport directions, especially to clear a jam as described above. This is optionally selected by the controller during cleaning mode, either generally or in cases of particularly heavy soiling (which can be detected, for example, by the feedback measurement described above). Alternatively, the controller may select such a change in transport direction, especially if, after cleaning mode (which was optionally performed with only one tone signal for the positive transport direction), the controller determines – particularly based on further feedback measurement or similar – that the soiling is still present.Preferably, after the, in particular multiple, changes of direction, the controller selects a partial signal (or tone signal) for the positive transport direction in order to transport the loosened contaminant out of the sound channel.

[0025] The controller is therefore optionally configured to output several consecutive tones, optionally with different characteristics, as part of the cleaning mode.

[0026] Additionally or alternatively, the controller is conveniently configured to calculate the absolute value (abs(...)) of the selected waveform (e.g., abs(sin(t)) for a sine wave) and output this to the loudspeaker to create a positive transmission direction. Similarly, the controller is also configured to calculate the negative absolute value (-abs(...)) of the waveform and output this to create a negative transmission direction.

[0027] Preferably, the controller is configured to select a frequency range of 50 Hz to 2000 Hz for the chirp. Here and in the following, "frequency range" refers specifically to the upper and lower limits of frequencies within which the chirp can be selected by the controller. The controller can select either a decreasing or increasing frequency.

[0028] For example, the controller is configured to select a chirp frequency range of 550 Hz to 50 Hz for contamination in the form of liquid (i.e., when the controller detects liquid as contamination in the sound conduction duct). If the controller detects dry particles as contamination in the sound conduction duct, it is additionally or alternatively configured to select a chirp frequency range of 100 Hz to 1500 Hz. Specifically, the controller is configured to select a starting frequency in the range of up to 550 Hz and a final frequency in the range of approximately 50 Hz when liquid is present in the sound conduction duct. For dry contaminants, starting frequencies are in the range of 100 Hz and final frequencies in the range of 1500 Hz. Thus, in the case of liquid, the chirp frequency decreases over its duration.In the case of dry soiling, the frequency tends to increase. However, the starting and ending frequency values ​​can also be reversed in both cases (dry particles and liquid) (i.e., the starting frequency is "low" and the ending frequency is "high," or vice versa).

[0029] According to a suitable further development, the controller is also configured to assign different frequency ranges within the frequency range to the chirp, depending on the length of the sound conduction duct. In particular, for a comparatively long duct, a frequency range shifted towards lower frequencies is assigned. In other words, the controller causes the loudspeaker to output a chirp with a comparatively low start and end frequency when the sound conduction duct is comparatively long. Optionally, a lookup table is stored in the controller's memory for this purpose, containing corresponding start and end frequencies for different lengths of the sound conduction duct.The length of the sound conduction channel can be particularly relevant for behind-the-ear hearing aids, as these typically use sound tubes that connect the loudspeaker located in the hearing aid's housing ("main housing") to the user's ear (ear canal) when in use. Standardized lengths of such sound tubes are usually available. These tubes are often coded (e.g., with a combination of numbers and / or letters) and entered by the user or a specialist into the controller, allowing the controller to read the information from the table described above.

[0030] According to a particularly preferred embodiment, the controller is configured to superimpose two chirps, differing in their respective frequency ranges within the frequency band and / or chirp duration, and to output them via the loudspeaker. In particular, the controller is configured to "shape" both chirps as described here and below. Preferably, the controller is configured to define each of these two chirps differently with respect to the described parameters, in particular their start and end frequencies, their chirp duration, and optionally their waveform. Such a superposition of (at least) two chirps is based on the understanding that the maximum sound output pressure of a loudspeaker is regularly frequency-dependent.Thus, when two frequency-shifted chirps are superimposed, a higher sound output pressure can be generated even for those frequency components of a chirp for which only a lower value would normally be possible. Furthermore, the sound propagation speed also differs for different frequencies. This can be advantageously used to add wavefronts at specific points (longitudinal positions) along the sound conduction channel and thus locally amplify their effect. For example, the superposition of (at least) two chirps can be used to allow the added wavefronts to successively "travel" through the sound conduction channel.The use of different chirps in superposition therefore also has the advantage that, due to their differences, various "contamination situations" in the sound channel (position, degree of possible blockage - complete or partial) can be "addressed", especially without having exact knowledge of the contamination situation.

[0031] In one embodiment involving two superimposed chirps, the controller, assuming a behind-the-ear hearing aid and water as a source of contamination, uses two chirps with a square waveform. The first chirp has a starting frequency of 410 Hz and a final frequency of 80 Hz, with a duration of 5 seconds (after which the chirp is repeated). The second chirp has a starting frequency of 520 Hz and a final frequency of 90 Hz, with a duration of 10 seconds.

[0032] Optionally, the controller repeats the sound signal, especially the chirp or superimposed chirps, several times if necessary.

[0033] According to a suitable embodiment, the controller is configured to recognize the intended wearing position of the hearing aid and to lock the cleaning mode or recommend (especially to the user) that the hearing aid be removed. For example, the hearing aid has an inertial measurement unit, in particular a 3D accelerometer, from whose output signal the controller infers the orientation of the hearing aid in space. Preferably, the controller is configured to recognize an orientation in space typical for the (intended) wearing position of the hearing aid on the head, in particular on the user's ear (e.g., based on one or more reference values) and then to lock the cleaning mode or recommend that the hearing aid be removed. In particular, the controller is configured to recommend (optionally in addition to removing) placing the hearing aid in a charger.This design has the advantage that the use of comparatively high sound levels in cleaning mode, which could otherwise lead to damage to the user's hearing, is unproblematic.

[0034] Preferably, the controller is configured to drive the loudspeaker to output the audio signal at a sound pressure level of 75 to 145 dB SPL, e.g., between 80 and 140 dB SPL. A minimum and / or maximum sound pressure level often depends on the hearing instrument, particularly on the length, diameter, and / or material of the sound transmission duct, and can be determined for the respective hearing instrument through simple testing.

[0035] According to a suitable embodiment, the controller is configured to select, in addition to the waveform and frequency range described above (i.e., in particular the start and end frequencies), an intensity for the cleaning mode depending on the type of contamination. This intensity can be varied, in particular, by the parameters (selectable by the controller) the total duration of the respective cleaning signal or cleaning mode (in the context of the above embodiments, in particular how often the respective tone signal(s), especially the respective chirp, is repeated) and / or the volume level.

[0036] According to an optional configuration, the controller is set up to perform a drying mode before the cleaning mode (i.e., before its activation). For this purpose, the controller instructs the loudspeaker to output a drying tone signal with a frequency below 20 Hz. This frequency is inaudible or virtually inaudible to the human ear, so the drying mode can be performed even during normal use of the hearing aid. This drying tone signal preferably causes sound-driven evaporation of moisture, particularly due to resulting air pressure fluctuations, but also—especially during prolonged operation of the loudspeaker—temperature-induced drying due to an increased operating temperature (particularly above an ambient temperature). This can, for example,Contamination with moist dust can be countered particularly effectively, as moisture is removed during the drying mode and dry particles can be effectively removed from the sound conduction channel during the subsequent cleaning mode.

[0037] According to an advantageous embodiment, the controller is configured to use the positioning of the hearing aid in a charger or the commencement of charging in the charger as a starting condition. That is, the controller initiates the cleaning mode when the hearing aid is placed in the charger—this can be detected, for example, by coupling with galvanic charging contacts or coupling with induction coils—or only when charging has begun. The latter is practical, at least insofar as it ensures a power supply for the cleaning mode, which is potentially more energy-intensive compared to normal operation of the hearing aid. Furthermore, this often also reduces acoustic disturbance to the user, since the charger preferably has a closable and thus at least partially acoustically encapsulated housing.Optionally, this start condition can also be used solely to determine, as described above, whether contamination is present, so that under this start condition the controller first checks for the presence of contamination and only activates the cleaning mode (in the sense of a second start condition) when contamination has been detected.

[0038] As an alternative start condition, the controller can optionally use the elapsed wearing time since the last activation of the cleaning mode or the expiration of a predefined waiting period (e.g., 24 or 48 hours). In this case, too, it is advisable to precede the cleaning with a check for the presence of contamination. Furthermore, detected environmental conditions can also be used as a start condition, at least for the initial check. For example, increased activity or physical exertion (e.g., jogging, cycling, swimming), which can usually be determined from the signal of the inertial measurement unit described above using appropriate algorithms and indicates the presence of perspiration and / or the risk of external moisture, can be used as a start condition. Similarly, the presence of rain, which in the case of a hearing aid might indicate, for example, that the device is wet, can also be used as a start condition.derived from microphone data or determined in a simple way using weather data, e.g., collected with a smartphone, can be used as such a starting condition.

[0039] Furthermore, the controller is also configured to use user activation of the cleaning mode as a starting condition. In this case, the controller preferably performs the aforementioned check for the presence of contamination and then selects the parameters (i.e., the waveform, frequency range, etc.) for the respective tone signal(s) as described above. Preferably, if no contamination is present, the controller is configured to prompt the user to decide whether the cleaning mode should still be performed. Optionally, a "general cleaning signal" is stored for this purpose, which, for example, contains an initial partial cleaning signal for moisture and a subsequent second partial cleaning signal for dry particles.

[0040] According to a further advantageous embodiment, the controller is configured to superimpose another acoustic signal, in particular a so-called jingle, on (or, if applicable, on any) the aforementioned tone signal (cleaning signal). This can be used to mask or "disguise" the cleaning signal, which usually sounds rather peculiar or disturbing to the user, and thus reduce any (even if only subjectively perceived) disturbance.

[0041] Within the scope of the invention, it is also conceivable that a reservoir (e.g., in the form of a chamber connected to the sound conduction channel) for particles or, optionally, moisture is arranged on the sound conduction channel – preferably at a short distance from the loudspeaker compared to the length of the sound conduction channel. In the case of negative transport direction, contaminants, especially particles, can be collected here and emptied periodically by the user.

[0042] The term "user" is to be understood as an equivalent, shortened term for a person using the hearing instrument without any reference to the gender of that person.

[0043] The conjunction "and / or" is to be understood here and in the following in particular as meaning that the features linked by means of this conjunction can be formed both jointly and as alternatives to each other.

[0044] Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. The drawing shows: Fig. 1 in a schematic representation of a hearing instrument system with a hearing instrument, Figs. 2-4 each in a schematic diagram a waveform of a sound signal output by means of a loudspeaker of the hearing instrument, and Figs. 5, 6 each in a schematic, diagrammatic representation the use of two different sound signals for the acoustically driven transport of contaminants through a sound conduction channel.

[0045] Corresponding parts and sizes are always marked with the same reference symbols in all figures.

[0046] In Fig. 1 The diagram schematically depicts a hearing aid system comprising a hearing instrument 1 in the form of a behind-the-ear hearing aid. The hearing instrument 1 has a front microphone 2 and a rear microphone 4, corresponding to its intended wearing position on the user's head. Furthermore, the hearing instrument 1 includes a signal processor 6, a loudspeaker 8, and a power source 10 (here, a rechargeable battery). The microphones 2 and 4, the signal processor 6, the loudspeaker 8, and the power source 10 are arranged in a housing 12 of the hearing instrument 1.

[0047] The signal processor 6 is configured to process ambient sound, which is captured by microphones 2 and 4 and converted into microphone signals MS, depending on the user's hearing impairment. Specifically, it filters and amplifies the sound in a frequency-dependent manner and outputs it as the output signal AS to the loudspeaker 8. The loudspeaker, in turn, converts the output signal AS into sound for output to the user's ear. The sound emitted by the loudspeaker 8 is delivered into the ear canal via a sound tube 14 connected to the housing 12, which is positioned in the ear canal using an earpiece 16. The sound tube 14 thus forms a sound conduction channel that acoustically connects the loudspeaker 8 to the environment.

[0048] Although a type of mechanical filter (e.g., a mesh) is usually arranged on the earpiece side of the sound tube 14 to prevent the entry of earwax, moisture and / or dust or similar contaminants can still penetrate the sound tube 4. This occurs, for example, during sports activities (e.g., due to perspiration).

[0049] The signal processor 6 (which forms a controller for the hearing instrument 1 and the hearing instrument system) is designed and intended to perform a "cleaning" of the sound tube, as described in more detail below, within a cleaning mode. For this purpose, the signal processor 6 checks for the presence of one or more start conditions for initiating the cleaning mode, initiates the cleaning mode if the respective start condition is present, and, within this mode, outputs an audio signal (hereinafter: "cleaning signal") via the loudspeaker 8 (in particular, at least one). The cleaning signal is formed by or contains a so-called chirp.

[0050] A chirp is understood to be an acoustic signal (i.e., a sound signal) whose frequency changes over time, e.g., increases or decreases. Fig. 2 This is exemplified in a diagram where a signal amplitude A is plotted against time t, and a chirp based on a triangular waveform is represented. The chirp's amplitude Ac is constant, while the frequency decreases—here continuously. The signal processor 6 is configured to output at least one chirp with a constant waveform and constant amplitude (in particular, a constant maximum amplitude value) as a cleaning signal. However, the signal processor 6 is also configured to specify the waveform, a start and end frequency, a signal duration (chirp duration), and optionally a volume value (amplitude or level) depending on the type of contamination. The signal processor 6 is configured to proceed according to the steps described in more detail below.

[0051] According to a first embodiment, a start condition is created by placing the hearing instrument 1 in a charger (not shown in detail; also referred to as a charging box). The signal processor 6 detects this by the presence of galvanic charging contacts or inductive coupling with a charging coil. If this start condition is met, the signal processor 6 first checks whether the sound tube 14 is contaminated. For this purpose, the signal processor 6 performs a feedback measurement, specifically an open-loop gain measurement. By comparing this measurement with stored data (in particular, the results of comparative measurements), the signal processor 6 can determine whether any contamination is present and, if so, whether the contamination consists of moisture and / or dry particles (e.g., dust, sand, etc.) in the sound tube 14.

[0052] If the signal processor 6 detects that contamination is present, the signal processor 6 uses this as a (second or further start condition) and activates the cleaning mode.

[0053] During cleaning mode, the signal processor 6 selects the chirp properties described above depending on the type of contamination.

[0054] The signal processor 6 selects the waveform from signal forms that exhibit many harmonics. These include, in addition to the one in Fig. 2 depicted triangular shape, among others, one in Fig. 3 (schematically represented for a constant frequency) rectangular shape and a in Fig. 4 (schematically represented for a constant frequency) sawtooth shape.

[0055] Additionally, the signal processor 6 selects a start frequency and an end frequency as well as a chirp duration (i.e. the duration in which the frequency is changed from the start to the end frequency).

[0056] In simple embodiments, the signal processor 6 selects a chirp with one of three waveforms, a start frequency of 550 Hz, an end frequency of 50 Hz, and a chirp duration of 5 seconds for liquid that has penetrated the sound tube 14. The signal processor 6 then plays this chirp back several times in succession (either as a partial signal of the cleaning signal or as multiple cleaning signals within the same cleaning mode), for example, 4 times.

[0057] The signal processor 6 then performs another open loop gain measurement, i.e., checks whether the contamination has already been removed and, if necessary, repeats the chirps (i.e., the respective cleaning signal(s)).

[0058] If, on the other hand, the signal processor 6 detects, for example, that dust is present in the sound tube 14, the signal processor selects a chirp with one of the three waveforms, preferably a sawtooth waveform, a starting frequency of 100 Hz and a final frequency of 1500 Hz. That is, the frequency is increased here. The signal processor selects a signal duration of 5 to 20 seconds.

[0059] For particularly effective cleaning, the signal processor 6 "superimposes" at least two chirps (superposition). For a result like in Fig. 1 In the described behind-the-ear hearing aid, the signal processor 6 selects two chirps with a square waveform of the same amplitude Ac for cleaning the sound tube 14 of liquid (water). The first chirp lasts 5 seconds, the second 10 seconds. This means the first chirp is already played twice while the second is being played. The first chirp has a starting frequency of 410 Hz and an ending frequency of 80 Hz, while the second chirp starts at 520 Hz and ends at 90 Hz.

[0060] In Fig 5 und 6 Two exemplary embodiments for a "control" of a transport direction T of the respective contaminant, indicated here by points 30, are shown. Fig. 5 Figure 1 shows an implementation where the transmission direction T is directed away from the loudspeaker 8. In this example, the signal processor 6 uses a chirp (the varying period or frequency is not shown in detail here) with a sawtooth waveform. The slope of the rising edge of the curve (wave, oscillation) is always significantly steeper than that of the falling edge. Alternatively (or additionally in the case of superposition), the signal processor 6 calculates an absolute value of the selected waveform, here the sawtooth (e.g., abs(sawtooth(t))), and outputs this value via the loudspeaker 8.

[0061] In Fig. 6For the opposite direction of transmission T, the "sawtooth profile" is chosen accordingly in reverse. The rising edge is therefore flatter than the falling edge of the signal. Alternatively, the signal processor calculates the negative absolute value of the sawtooth (-abs(sawtooth(t))) and outputs it via the loudspeaker.

[0062] In an optional embodiment, the controller is configured to change the transport direction T multiple times by successively outputting several of the cleaning signals described above in order to dislodge the contamination. In this case, a comparatively long (e.g., 10 seconds) cleaning signal or several identical cleaning signals, in particular again a chirp each, with the transport direction T directed away from the loudspeaker, can follow the multiple changes in direction to then transport the dislodged contamination out of the sound tube 14.

[0063] The subject matter of the invention is not limited to the embodiments described above. Rather, further embodiments of the invention can be derived by a person skilled in the art from the foregoing description. In particular, the individual features of the invention and their various configurations described with reference to the different embodiments can also be combined with one another in other ways. Reference symbol list

[0064] 1 Hearing instrument 2 Microphone 4 Microphone 6 Signal processor 8 Speaker 10 Power source 12 Housing 14 Sound tube 16 Earpiece 30 Points MS Microphone signal AS Output signal A Signal amplitude t Time Ac Amplitude T Transport direction

Claims

1. Hearing instrument system comprising - a hearing instrument (1), - at least one loudspeaker (8) acoustically connected to the environment of the hearing instrument (1) via a sound conduction channel (14), and - a controller (6) configured to: + determine whether at least one start condition for initiating a cleaning mode for the sound conduction channel (14) is present, + initiate the cleaning mode when the or one of possibly several start conditions is present, + during the cleaning mode emit an audio signal with a waveform by means of the loudspeaker (8) and to vary the period of the waveform of the audio signal while the audio signal is being emitted.

2. Hearing instrument system according to claim 1, wherein the controller (6) is configured to emit a chirp as a tone signal with varying period.

3. Hearing instrument system according to claim 1 or 2, wherein the controller (6) is configured to detect a type of contamination of the sound conduction channel (14) and to select the waveform for the sound signal, in particular the chirp, depending on the contamination.

4. Hearing instrument system according to one of claims 1 to 3, wherein the controller (6) is configured to determine a type of contamination of the sound conduction channel (14) and to select a frequency range for the sound signal, in particular the chirp, depending on the contamination.

5. Hearing instrument system according to claim 3 or 4,wherein the controller (6) is configured to perform a feedback measurement, in particular acoustic, to determine the type of contamination of the sound conducting channel (14) and / or to determine a resonance detuning of the hearing instrument and / or to evaluate an optical recording, in particular of an inside, of the sound conducting channel (14).

6. Hearing instrument system according to one of claims 3 to 5, wherein the controller (6) is configured to select a rectangular shape or a sawtooth shape as the waveform for the sound signal, in particular the chirp.

7. Hearing instrument system according to claim 6, wherein the controller (6) is configured to select the sawtooth waveform for the sound signal, in particular the chirp, and to select a slope of the rising flank and the falling flank of the sawtooth depending on a transport direction (T) within the sound conduction channel (14).

8. Hearing instrument system according to claim 7, wherein the controller (6) is configured to select, within the cleaning mode, the tone signal or at least two successive tone signals such that the transport direction (T) changes.

9. Hearing instrument system according to any one of claims 2 to 8, wherein the controller (6) is configured to select a frequency range for the chirp from 50 Hz to 2000 Hz.

10. Hearing instrument system according to claim 9, wherein the controller (6) is configured to select a frequency range for the chirp of 550 Hz to 50 Hz for contamination in the form of liquid and / or a frequency range for the chirp of 100 Hz to 1500 Hz for contamination in the form of dry particles.

11. Hearing instrument system according to claim 9 or 10, wherein the controller (6) is configured to assign different frequency ranges within the frequency range to the chirp depending on the length of the sound conduction channel (14), in particular for a comparatively large length a frequency range shifted to lower frequencies.

12. Hearing instrument system according to one of claims 2 to 11, wherein the controller (6) is configured to superimpose two chirps differing in their frequency range within the frequency frame range and / or chirp duration as an audio signal and to output them by means of the loudspeaker.

13. Hearing instrument system according to one of claims 1 to 12, wherein the controller (6) is configured to recognize an intended wearing situation of the hearing instrument (1) and to lock the cleaning mode or to recommend putting the hearing instrument (1) away.

14. Hearing instrument system according to any one of claims 1 to 13, wherein the controller (6) is configured to perform a drying mode prior to the cleaning mode, in which a tone signal with a frequency below 20 Hz is output by means of the loudspeaker (8).

15. Hearing instrument system according to one of claims 1 to 14, wherein the controller (6) is configured to use as a start condition a positioning of the hearing instrument (1) in a charger or the commencement of a charging operation in the charger.

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